In many of today's vehicles, sensors that sense a rotating target wheel may be used for different applications. For example, a target wheel may be engaged with a vehicle crankshaft for inducing signals in one or more sensors positioned next to the target wheel, with the signals representing the angular position of the crankshaft. These position signals can be used in distributorless ignition systems that have selectively energized ignition coils that fire the spark plugs as appropriate for the angular position of the crankshaft. Moreover, the crankshaft angular position signals can be used for combustion control and diagnostic functions.
Essentially, the edge of the disk-shaped wheel is varied along the periphery of the wheel in some fashion, e.g., by cutting slots in the periphery in a predetermined pattern. Usually, one or two sensors are used to detect the slots as they pass by the sensors, with the detected slot pattern being correlated to a crankshaft angular position and, when two sensors are used, also to a crankshaft direction of rotation. Unfortunately, the present state of the art sensors of the above variety may be expensive and, in turn, increase manufacturing and production costs. The present invention has recognized the above-noted problems and has provided the below solutions to one or more of the above-noted problems.